Three-quarters of the state’s native fish are in trouble, and options for recovery have been constrained by the drought. We talked to Peter Moyle—an eminent fish biologist at UC Davis’s Center for Watershed Sciences and a member of the PPIC Water Policy Center research network—about what can be done to bring native fish back from the brink.
PPIC: A year ago, your research showed that if the drought continued, 18 native fish would be at imminent risk of extinction. What is the situation now, and how has the state responded?
Peter Moyle: For many native species, things are even worse. Those 18 species are in the most immediate danger, and their situation has not improved. Delta smelt are on the verge of extinction. We currently know of 122 species of native fish in California, and 90 of them are in trouble in one way or the other, with 30 already listed under the Endangered Species Act. Climate change is making things worse.
The fish agencies have mostly used emergency-room responses during this drought. For example, the California Department of Fish and Wildlife did some emergency rescue operations this summer—capturing fish and putting them in hatcheries. And the US Fish and Wildlife Service sent some large experimental flows into the Delta to try to help smelt. What we really need to do is get better about planning for managing our species and ecosystems through droughts and floods, both of which are regular features of the state’s climate.
PPIC: What are your top three recommendations for managing water to prevent extinctions?
PM: The first thing is to ensure that every species has a home. We need to designate and manage “conservation waters”—core habitats to protect native species.
Second, I would ensure that every dam that blocks a stream has a more natural flow regime that favors fish. We need a systematic evaluation of the state’s 1,500 large dams to see which could be better managed to provide flows for native fish. Since virtually every river in the state has a dam, there’s a lot of room for improvement. Putah Creek is a good example of the potential—its flow is designed to mimic natural flow patterns but using a much smaller amount of water than historic flows. Fish in that stream are doing really well right now.
Third, we need to be more realistic about managing the Delta for native species. The big programs to try to fix the entire Delta just don’t work from a native fish perspective. The southern and central Delta have been so altered by human activities that it is very hard to make the changes that would make a difference. More promising is focusing on an arc of habitat in the north Delta that is all linked by the Sacramento River, from the Yolo Bypass to Suisun Marsh. Investing in habitat restoration there could make a big difference. Also, if we cluster projects in one area, they can build on each other’s ecosystem benefits. It’s a much more likely place to have a successful restoration.
PPIC: What are your thoughts about the recent effort to help the Delta smelt with flows through the Yolo Bypass?
PM: I’m hopeful about this project, which is being led by Ted Sommer of the Department of Water Resources. The idea is to expand food sources for the smelt by moving water into the Yolo Bypass, where it becomes enriched with nutrients and plankton. The water is then flushed downstream where it stimulates more plankton growth. The DWR team found plankton blooms all the way to Rio Vista. It seems to have worked, but it’s still in the proof-of-concept stage. It will be good to try on a larger scale. This is a good example of reconciliation ecology—the idea that while we can’t re-create ecosystems from the past, we can try to create conditions that will allow species to thrive within altered systems. The potential to improve habitat for native species based on reconciliation ecology is huge.
PPIC: What else gives you hope?
PM: I’m an intrinsic optimist. One thing that gives me hope is that there are a lot of very bright people working to conserve fish in this state. And there have been some recent developments in water law that make me hopeful. The major thing we’re short of is the will at high levels to do the kinds of extensive, risky projects that could bring our fish back to healthy populations. A good example of what I’m talking about is happening at Blue Creek in the Klamath Basin, which is an important cold-water refuge for migrating salmon and steelhead. The entire watershed is being purchased so it can be managed for fish by the local Yurok tribe, who’ve agreed to be its stewards. The Western Rivers Conservancy, which is partnering with the Yurok, has been extremely creative in finding funding for the project. Not only does this project help fish, it helps preserve the Yurok’s cultural traditions and creates jobs for tribal members.
Read “California’s Ecosystems in Perpetual Drought” (PPIC Blog, August 30, 2016)
Read “Saving Native Fishes from Extinction” (PPIC Blog, October 30, 2015)
Read the report, What if California’s Drought Continues? (August 2015)